Hey, guys. I've been puzzling over this problem for a few days now. I need to make a mould for a part that's got a hole in it, specifically it is the top hull part of a model tank. The hole has notches in it that allow for the turret to lock in and rotate freely. How would you guys mould something like this? Plug up the hole and then cut it out for each casting? Just go with a split mould, maybe?